A medical imaging apparatus is an apparatus for obtaining images of internal structures of an object. A medical imaging apparatus that is a noninvasive investigation apparatus images, processes, and shows structural details in a body, internal structures, and fluid flow to a user. A user such as a doctor may diagnose a health condition and a disease of a patient by using a medical image output from a medical imaging apparatus.
Examples of a medical imaging apparatus include a magnetic resonance imaging (MRI) apparatus for providing a magnetic resonance (MR) image, a computed tomography (CT) apparatus, an X-ray apparatus, and an ultrasound diagnosis apparatus.
In detail, an MRI apparatus that is an apparatus for imaging a subject by using a magnetic field is widely used to accurately diagnose a disease because the MM apparatus shows not only bones but also the spine, joints, nerves, ligaments, and the like, at desired angles in a three-dimensional (3D) manner.
An MRI apparatus obtains an MR signal by using a high-frequency multi-coil including radio frequency (RF) coils, a permanent magnet, and a gradient coil. The MM apparatus reconstructs an MR image by sampling the MR signal.
When a medical imaging apparatus images an object, excessive current flowing through the medical imaging apparatus may damage a patient's body. Accordingly, an apparatus for monitoring and adjusting an intensity of current is necessary. In an embodiment, when excessive current flows due to electromagnetic induction through an RF receiving coil that is close to the patient's body, the patient's body may be burned.
Examples of a method of adjusting an intensity of current flowing through an RF receiving coil include a method of maintaining current flowing through a circuit at a low level by using a decoupling circuit having a high independence. However, since the decoupling circuit has an impendence that varies according to an RF, over-current may be generated according to a frequency of the MRI apparatus.
Accordingly, one of the most commonly used methods is a method using a fuse. In the method using the fuse, a circuit may be turned off when over-current is generated.